Re: [Xen-devel] [PATCH] x86/HVM: refine SMEP/SMAP tests in HVM_CR4_GUEST_RESERVED_BITS()

[David Vrabel <david.vrabel@xxxxxxxxxx>]

On 05/06/14 12:58, Jan Beulich wrote:
> Andrew validly points out that the use of the macro on the restore path
> can't rely on the CPUID bits for the guest already being in place (as
> their setting by the tool stack in turn requires the other restore
> operations already having taken place). And even worse, using
> hvm_cpuid() is invalid here because that function assumes to be used in
> the context of the vCPU in question.
> 
> Reverting to the behavior prior to the change from checking
> cpu_has_sm?p to hvm_vcpu_has_sm?p() would break the other (non-restore)
> use of the macro. So let's revert to the prior behavior only for the
> restore path, by adding a respective second parameter to the macro.
> 
> Obviously the two cpu_has_* uses in the macro should really also be
> converted to hvm_cpuid() based checks at least for the non-restore
> path.

FWIW,

Tested-by: David Vrabel <david.vrabel@xxxxxxxxxx>

But on 4.4.x not unstable.

David

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